7z0k

Structural highlights

Disease

PEX5_HUMAN Defects in PEX5 are the cause of peroxisome biogenesis disorder 2A (PBD2A) [MIM:214110. A fatal peroxisome biogenesis disorder belonging to the Zellweger disease spectrum and characterized clinically by severe neurologic dysfunction with profound psychomotor retardation, severe hypotonia and neonatal seizures, craniofacial abnormalities, liver dysfunction, and biochemically by the absence of peroxisomes. Additional features include cardiovascular and skeletal defects, renal cysts, ocular abnormalities, and hearing impairment. Most severely affected individuals with the classic form of the disease (classic Zellweger syndrome) die within the first year of life.^[1] Defects in PEX5 are the cause of peroxisome biogenesis disorder 2B (PBD2B) [MIM:202370. A peroxisome biogenesis disorder that includes neonatal adrenoleukodystrophy (NALD) and infantile Refsum disease (IRD), two milder manifestations of the Zellweger disease spectrum. The clinical course of patients with the NALD and IRD presentation is variable and may include developmental delay, hypotonia, liver dysfunction, sensorineural hearing loss, retinal dystrophy and vision impairment. Children with the NALD presentation may reach their teens, while patients with the IRD presentation may reach adulthood. The clinical conditions are often slowly progressive in particular with respect to loss of hearing and vision. The biochemical abnormalities include accumulation of phytanic acid, very long chain fatty acids (VLCFA), di- and trihydroxycholestanoic acid and pipecolic acid.PEX13_HUMAN Zellweger syndrome;Neonatal adrenoleukodystrophy;Infantile Refsum disease. The disease is caused by variants affecting the gene represented in this entry. The disease is caused by variants affecting the gene represented in this entry. The disease is caused by variants affecting the gene represented in this entry.

Function

PEX5_HUMAN Binds to the C-terminal PTS1-type tripeptide peroxisomal targeting signal (SKL-type) and plays an essential role in peroxisomal protein import.^{[2] [3] [4]} PEX13_HUMAN Component of the PEX13-PEX14 docking complex, a translocon channel that specifically mediates the import of peroxisomal cargo proteins bound to PEX5 receptor (PubMed:9653144, PubMed:8858165, PubMed:28765278). The PEX13-PEX14 docking complex forms a large import pore which can be opened to a diameter of about 9 nm (By similarity). Mechanistically, PEX5 receptor along with cargo proteins associates with the PEX14 subunit of the PEX13-PEX14 docking complex in the cytosol, leading to the insertion of the receptor into the organelle membrane with the concomitant translocation of the cargo into the peroxisome matrix (PubMed:9653144, PubMed:8858165, PubMed:28765278). Involved in the import of PTS1- and PTS2-type containing proteins (PubMed:9653144, PubMed:8858165).[UniProtKB:P80667]^{[5] [6] [7]}

References

1. ↑ Dodt G, Braverman N, Wong C, Moser A, Moser HW, Watkins P, Valle D, Gould SJ. Mutations in the PTS1 receptor gene, PXR1, define complementation group 2 of the peroxisome biogenesis disorders. Nat Genet. 1995 Feb;9(2):115-25. PMID:7719337 doi:http://dx.doi.org/10.1038/ng0295-115
2. ↑ Dodt G, Braverman N, Wong C, Moser A, Moser HW, Watkins P, Valle D, Gould SJ. Mutations in the PTS1 receptor gene, PXR1, define complementation group 2 of the peroxisome biogenesis disorders. Nat Genet. 1995 Feb;9(2):115-25. PMID:7719337 doi:http://dx.doi.org/10.1038/ng0295-115
3. ↑ Wiemer EA, Nuttley WM, Bertolaet BL, Li X, Francke U, Wheelock MJ, Anne UK, Johnson KR, Subramani S. Human peroxisomal targeting signal-1 receptor restores peroxisomal protein import in cells from patients with fatal peroxisomal disorders. J Cell Biol. 1995 Jul;130(1):51-65. PMID:7790377
4. ↑ Fransen M, Brees C, Baumgart E, Vanhooren JC, Baes M, Mannaerts GP, Van Veldhoven PP. Identification and characterization of the putative human peroxisomal C-terminal targeting signal import receptor. J Biol Chem. 1995 Mar 31;270(13):7731-6. PMID:7706321
5. ↑ Dias AF, Rodrigues TA, Pedrosa AG, Barros-Barbosa A, Francisco T, Azevedo JE. The peroxisomal matrix protein translocon is a large cavity-forming protein assembly into which PEX5 protein enters to release its cargo. J Biol Chem. 2017 Sep 15;292(37):15287-15300. PMID:28765278 doi:10.1074/jbc.M117.805044
6. ↑ Gould SJ, Kalish JE, Morrell JC, Bjorkman J, Urquhart AJ, Crane DI. Pex13p is an SH3 protein of the peroxisome membrane and a docking factor for the predominantly cytoplasmic PTs1 receptor. J Cell Biol. 1996 Oct;135(1):85-95. PMID:8858165 doi:10.1083/jcb.135.1.85
7. ↑ Fransen M, Terlecky SR, Subramani S. Identification of a human PTS1 receptor docking protein directly required for peroxisomal protein import. Proc Natl Acad Sci U S A. 1998 Jul 7;95(14):8087-92. PMID:9653144 doi:10.1073/pnas.95.14.8087